Chest Pain: A Comprehensive Guide to Differential Diagnosis and Up-to-Date Evaluation

Chest pain is a frequently encountered complaint in clinical practice, presenting a significant diagnostic challenge due to its extensive differential diagnosis. This broad spectrum ranges from benign conditions to life-threatening emergencies, necessitating a systematic and thorough approach to patient evaluation. Ruling out serious etiologies such as acute coronary syndromes, pulmonary embolism, and aortic dissection is paramount before considering less critical causes. Understanding the nuances of chest pain, including its diverse presentations and underlying pathologies, is crucial for healthcare professionals. This article provides an uptodate review of chest pain differential diagnosis, evaluation strategies, and initial management, aiming to enhance clinical decision-making and patient outcomes.

Etiology of Chest Pain: Understanding Visceral and Somatic Pain

When evaluating chest pain, differentiating between visceral and somatic pain can offer valuable diagnostic clues. Visceral pain, originating from the internal organs, is often described as vague and poorly localized. Patients typically struggle to pinpoint the pain with a single finger, instead gesturing to a broader area. Common descriptors include dull, deep, pressure-like, or squeezing sensations. A key characteristic of visceral pain is its potential for referred pain. This phenomenon occurs because visceral sensory nerves converge with somatic nerve fibers as they ascend to the spinal cord. For instance, ischemic cardiac pain may radiate to the left or right shoulder, jaw, or left arm. Associated symptoms like nausea and vomiting can further suggest a visceral origin. Irritation of the diaphragm, another source of visceral pain, can also refer pain to the shoulders.

In contrast, somatic pain arises from the musculoskeletal system or skin and is typically more localized and easier for patients to describe precisely. Individuals experiencing somatic chest pain can usually point to the specific area of discomfort. Referred pain is less common with somatic pain. Descriptors often used for somatic pain include sharp, stabbing, or poking. Differentiating these pain characteristics, while not definitive, aids in narrowing the differential diagnosis of chest pain.

Epidemiology: Chest Pain in the Emergency Department

Chest pain is a prevalent complaint in emergency departments (EDs), ranking as the second most common reason for visits and accounting for approximately 5% of all ED presentations. Given the potential for life-threatening underlying conditions, a high index of suspicion and a structured evaluation are essential. Studies have highlighted the distribution of diagnoses in patients presenting to the ED with chest pain. Fruergaard et al. found the following approximate percentages for critical conditions:

• Acute Coronary Syndrome (ACS): 31%
• Pulmonary Embolism (PE): 2%
• Pneumothorax (PTX): Unreported
• Pericardial Tamponade: Unreported (Pericarditis 4%)
• Aortic Dissection: 1%
• Esophageal Perforation: Unreported

Other common, though less immediately life-threatening, causes of chest pain in the ED setting include:

• Gastrointestinal Reflux Disease (GERD): 30%
• Musculoskeletal Causes: 28%
• Pneumonia/Pleuritis: 2%
• Herpes Zoster: 0.5%
• Pericarditis: Unreported

These epidemiological data underscore the importance of considering both high-risk and common etiologies in the differential diagnosis of chest pain in the emergency setting.

History and Physical Examination: Key to Chest Pain Evaluation

A comprehensive history and physical examination are the cornerstones of chest pain evaluation. The history should begin with a detailed exploration of the patient’s chief complaint, using mnemonics like OLD CARTS to guide questioning:

History

• Onset: When did the pain begin? What were you doing when it started? Was it triggered by exertion or at rest?
• Location: Can you point to the pain with one finger, or is it diffuse?
• Duration: How long does the pain episode last?
• Character: How would you describe the pain? (e.g., sharp, dull, pressure, squeezing, stabbing)
• Aggravating/Alleviating Factors: What makes the pain worse or better? Is it related to exertion, eating, breathing, or body position? Inquire about new workout routines, sports, or lifting activities. What medications have you tried?
• Radiation: Does the pain radiate to other areas like the arm, jaw, or back?
• Timing: How frequently do you experience this pain? How long are you pain-free between episodes?

In addition to pain characteristics, inquire about associated symptoms:

• Shortness of breath
• Nausea and vomiting
• Fever
• Diaphoresis (sweating)
• Cough
• Dyspepsia (indigestion)
• Edema (swelling)
• Calf pain or swelling
• Recent illness

Risk factor assessment is crucial for stratifying patients and guiding the chest pain differential diagnosis. Evaluate for risk factors associated with:

• Acute Coronary Syndrome (ACS): Prior myocardial infarction (MI), family history of cardiac disease, smoking, hypertension (HTN), hyperlipidemia (HLD), diabetes.
• Pulmonary Embolism (PE): Prior deep venous thrombosis (DVT) or PE, hormone use (including oral contraceptives), recent surgery, cancer, prolonged immobility.
• Recent gastrointestinal (GI) procedures (e.g., endoscopy).
• Drug abuse, particularly cocaine and methamphetamines.

Obtain a thorough past medical history, noting cardiac conditions, coagulopathies, and kidney disease. Family history, especially of cardiac disease, and social history, including tobacco and drug use, are also relevant.

After addressing life-threatening possibilities, consider other common causes. Inquire about productive cough or recent upper respiratory infection (URI) symptoms suggestive of pneumonia. GERD symptoms like heartburn or acid reflux should be explored. New exercise routines or recent trauma may point towards musculoskeletal pain.

Physical Examination

The physical exam should be systematic and include:

• Vital Signs: Complete set, including blood pressure (BP) in both arms to assess for aortic dissection.
• General Appearance: Note diaphoresis, distress level, and overall appearance.
• Skin Exam: Inspect for lesions, particularly vesicular rash of herpes zoster (shingles).
• Neck Exam: Assess for jugular venous distension (JVD), especially with inspiration (Kussmaul sign), which can indicate pericardial tamponade or heart failure.
• Chest Examination: Palpate for areas of reproducible pain, crepitus (suggesting subcutaneous air), and chest wall abnormalities.
• Heart Exam: Auscultate heart sounds for murmurs, rubs, or gallops.
• Lung Exam: Auscultate breath sounds for wheezes, crackles, or diminished breath sounds.
• Abdominal Exam: Palpate for tenderness, guarding, or rebound.
• Extremities Exam: Assess for unilateral swelling, calf tenderness (DVT), edema, and presence and equality of peripheral pulses.

The history and physical exam, when combined, are essential for formulating a targeted chest pain differential diagnosis and guiding subsequent investigations.

Evaluation of Chest Pain: Diagnostic Modalities

The evaluation of chest pain often follows established protocols, particularly in emergency settings, to efficiently rule out critical conditions. Minimum initial investigations typically include:

• Electrocardiogram (ECG): Ideally obtained within the first 10 minutes of arrival and repeated serially to detect evolving ischemic changes. Serial ECGs are crucial for capturing dynamic changes indicative of ACS.
• Chest X-ray: To evaluate for pneumothorax, pneumonia, pleural effusion, and mediastinal widening suggestive of aortic dissection or esophageal rupture.
• Complete Blood Count (CBC), Basic Metabolic Panel (BMP), Troponin Level: CBC and BMP provide baseline metabolic and hematologic status. Serial troponin levels, typically drawn 4 hours apart, are essential for detecting myocardial injury in ACS. Lipase may be considered if pancreatitis is suspected in the differential diagnosis of chest pain, although it is less common as a primary cause.

Further investigations are guided by the initial assessment and clinical suspicion:

• Computed Tomography Pulmonary Angiography (CTPA): The gold standard for diagnosing pulmonary embolism (PE).
• Ventilation-Perfusion (VQ) Scan: An alternative to CTPA when CT contrast is contraindicated, although less sensitive and specific, particularly in patients with pre-existing lung disease.
• Bedside Ultrasound (US): Rapidly assess for pericardial effusion and tamponade in hemodynamically unstable patients.

These diagnostic tools, used judiciously based on the clinical context, facilitate a timely and accurate differential diagnosis of chest pain.

Treatment and Management Based on Differential Diagnosis

Management of chest pain is dictated by the underlying etiology. Prompt recognition and treatment of life-threatening conditions are paramount.

Acute Coronary Syndrome (ACS)

Initial management of suspected ACS involves:

• Continuous cardiac monitoring.
• Intravenous (IV) access.
• Aspirin administration (162-325 mg chewable).
• Antiplatelet therapy with clopidogrel or ticagrelor (unless urgent bypass surgery is anticipated).
• Pain control, typically with nitroglycerin and morphine if needed.
• Oxygen therapy if hypoxemic.

Nitroglycerin can reduce mortality in ACS and aims for a 10% reduction in mean arterial pressure (MAP) in normotensive patients and a 30% reduction in hypertensive patients. Avoid nitroglycerin in hypotensive patients or those with inferior ST-elevation myocardial infarction (STEMI) due to potential preload reduction.

Patients with STEMI on ECG require immediate reperfusion therapy, preferably percutaneous coronary intervention (PCI). PCI should be performed within 90 minutes of arrival at a PCI-capable center or within 120 minutes if transfer is required. If PCI is not feasible within these timeframes, thrombolytic therapy should be initiated within 30 minutes of arrival.

Patients with non-ST elevation myocardial infarction (NSTEMI) or unstable angina require hospital admission for cardiology consultation and further workup, including risk stratification and consideration for angiography. Stable angina may be managed in the outpatient setting. Elderly patients and those with comorbidities often warrant admission for observation and further cardiac evaluation.

Pulmonary Embolism (PE)

For suspected PE, CTPA is the preferred confirmatory test. VQ scan is an alternative when CTPA is contraindicated. Hemodynamically unstable patients with confirmed or highly suspected PE should receive thrombolytic therapy. Stable patients should be initiated on anticoagulation.

Pneumothorax (PTX)

Tension pneumothorax requires immediate decompression, typically with needle thoracostomy followed by chest tube placement. Non-tension pneumothorax management depends on size and patient stability but often involves chest tube insertion.

Pericardial Tamponade

Bedside ultrasound is invaluable for diagnosing pericardial tamponade. Initial management includes fluid resuscitation as a temporizing measure. Definitive treatment requires pericardiocentesis (needle drainage of pericardial fluid) or surgical pericardial window to relieve pressure on the heart.

Aortic Dissection

Aortic dissection is a surgical emergency requiring early cardiothoracic surgery consultation. CT angiography is the diagnostic test of choice. Immediate management includes establishing two large-bore IV lines and rapidly lowering systolic blood pressure to 100-120 mmHg, typically using intravenous beta-blockers to reduce heart rate and blood pressure, thus minimizing aortic wall stress.

Esophageal Perforation

Esophageal perforation is a medical emergency often suggested by left pleural effusion on chest X-ray. Contrast esophagram is the confirmatory test. Immediate surgical consultation is warranted.

Gastroesophageal Reflux Disease (GERD)

While GERD is a common cause of chest pain, it’s crucial to rule out cardiac etiologies first, as ACS can sometimes mimic GERD symptoms. A “GI cocktail” (viscous lidocaine and Maalox) can be administered for symptomatic relief, but it is not diagnostic and should not delay evaluation for serious conditions. Long-term GERD management involves proton pump inhibitors (PPIs) or H2 receptor antagonists.

Differential Diagnosis of Chest Pain: A Broad Spectrum

The differential diagnosis of chest pain is extensive and includes, but is not limited to:

• Acute Coronary Syndrome (ACS)
• Aortic Dissection
• Pulmonary Embolism (PE)
• Gastroesophageal Reflux Disease (GERD)
• Musculoskeletal Chest Pain
• Esophageal Rupture (Boerhaave Syndrome)
• Pericarditis
• Pneumonia
• Herpes Zoster (Shingles)
• Pneumothorax
• Cervical Radiculopathy
• Esophageal Spasm

This broad list emphasizes the complexity of chest pain evaluation and the need for a systematic approach to arrive at an accurate diagnosis.

Pearls and Key Considerations in Chest Pain Diagnosis

• Aortic dissection can present with stroke symptoms. Always consider aortic dissection in the differential diagnosis of chest pain, especially in patients with neurological deficits or pulse deficits.
• Younger patients and those without traditional risk factors can still experience myocardial infarction. Do not rely solely on age or risk factors to exclude ACS.
• Diabetic and elderly patients may have atypical presentations of ACS due to neuropathy. Be vigilant for subtle or atypical chest pain symptoms in these populations. They may present with shortness of breath, fatigue, or nausea without classic chest pain.

Enhancing Healthcare Team Outcomes

Effective management of chest pain necessitates a collaborative interprofessional team approach. Nurse practitioners, primary care providers, internists, emergency department physicians, and surgeons all play crucial roles in the evaluation and care of patients with chest pain. A thorough medical history, obtained by any member of the team, often provides critical clues to the diagnosis. The key is to maintain a high level of vigilance to avoid missing life-threatening conditions such as acute MI or aortic dissection. When the cause of chest pain remains uncertain after initial evaluation, referral to a specialist, such as a cardiologist, pulmonologist, or gastroenterologist, is recommended. Patient outcomes in chest pain depend heavily on the underlying cause and the timeliness of appropriate interventions. Continuous professional development and adherence to uptodate guidelines are essential for all healthcare professionals involved in the care of patients with chest pain to optimize diagnostic accuracy and improve patient outcomes.

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Disclosures: Ken Johnson declares no relevant financial relationships with ineligible companies.

Disclosures: Sassan Ghassemzadeh declares no relevant financial relationships with ineligible companies.